U.S. patent number 10,913,441 [Application Number 16/954,636] was granted by the patent office on 2021-02-09 for integrated powertrain control of engine and transmission.
This patent grant is currently assigned to Cummins, Inc.. The grantee listed for this patent is Cummins, Inc.. Invention is credited to Rohit Saha.
United States Patent |
10,913,441 |
Saha |
February 9, 2021 |
Integrated powertrain control of engine and transmission
Abstract
Systems and apparatuses of a vehicle include an engine control
circuit structured to control an engine speed, a transmission
control circuit structured to control a transmission, an implement
control circuit structured to control an implement, and a
processing circuit structured to receive a travel signal indicative
of a travel mode for the vehicle, or an implement signal indicative
of an implement mode for the vehicle. In response to operating in
the travel mode, the transmission control circuit determines the
engine speed and the implement control circuit limits an implement
torque to maintain the engine speed. In response to operating in
the implement mode, the engine control circuit determines the
engine speed and the transmission control circuit limits a
propulsion torque to maintain the engine speed.
Inventors: |
Saha; Rohit (Columbus, IN) |
Applicant: |
Name |
City |
State |
Country |
Type |
Cummins, Inc. |
Columbus |
IN |
US |
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Assignee: |
Cummins, Inc. (Columbus,
IN)
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Family
ID: |
1000005349874 |
Appl.
No.: |
16/954,636 |
Filed: |
December 17, 2018 |
PCT
Filed: |
December 17, 2018 |
PCT No.: |
PCT/US2018/066031 |
371(c)(1),(2),(4) Date: |
June 17, 2020 |
PCT
Pub. No.: |
WO2019/126051 |
PCT
Pub. Date: |
June 27, 2019 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20200317182 A1 |
Oct 8, 2020 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62607178 |
Dec 18, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E02F
9/2066 (20130101); B60W 10/101 (20130101); E02F
9/2079 (20130101); E02F 9/2012 (20130101); B60W
30/188 (20130101); E02F 9/2033 (20130101); B60W
10/04 (20130101); B60W 2300/17 (20130101); B60W
2540/10 (20130101); B60W 2510/0657 (20130101); B60W
2710/0644 (20130101) |
Current International
Class: |
B60W
10/06 (20060101); B60W 30/188 (20120101); B60W
10/04 (20060101); B60W 10/101 (20120101); E02F
9/20 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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WO-2009/145706 |
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Dec 2009 |
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WO |
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Other References
International Search Report and Written Opinion for International
Application No. PCT/US2018/066031, dated Mar. 11, 2019, 9 pages.
cited by applicant.
|
Primary Examiner: Young; Edwin A
Attorney, Agent or Firm: Foley & Lardner LLP
Parent Case Text
RELATED APPLICATIONS
This application claims the benefit of and priority to U.S.
Provisional Patent Application No. 62/607,178, entitled "Integrated
Powertrain Control of Engine and Transmission," filed on Dec. 18,
2017, which is incorporated herein by reference in its entirety.
Claims
What is claimed is:
1. An apparatus of a vehicle, comprising: an engine control circuit
structured to control an engine speed; a transmission control
circuit structured to control an operating parameter of a
transmission; an implement control circuit structured to control an
implement; and a processing circuit structured to receive one of a
travel signal indicative of a travel mode for the vehicle and an
implement signal indicative of an implement mode for the vehicle,
in response to receiving the travel signal indicative of operating
in the travel mode, the transmission control circuit is structured
to determine the engine speed and the implement control circuit
limits an implement torque to maintain the engine speed; and in
response to receiving the implement signal indicative of operating
in the implement mode, the engine control circuit is structured to
determine the engine speed and the transmission control circuit
limits a propulsion torque to maintain the engine speed.
2. The apparatus of claim 1, wherein the engine control circuit is
structured to determine a torque reserve, and wherein the
processing circuit is structured to compare the torque reserve to a
torque reserve threshold, in response to the torque reserve being
less than or equal to the torque reserve threshold and the vehicle
operating in the travel mode, the implement control circuit limits
the implement torque, and in response to the torque reserve being
less than or equal to the torque reserve threshold and the vehicle
operating in the implement mode, the transmission control circuit
limits the propulsion torque.
3. The apparatus of claim 1, wherein the engine control circuit is
structured to determine a minimum fuel consumption torque, and
wherein the processing circuit is structured to determine a total
torque demand and to compare the total torque demand to the minimum
fuel consumption torque, in response to the total torque demand
being greater than or equal to the minimum fuel consumption torque
and the vehicle operating in the travel mode, the transmission
control unit is structured to change the engine speed, and in
response to the total torque demand being greater than or equal to
the minimum fuel consumption torque and the vehicle operating in
the implement mode, the transmission control circuit is structured
to change a transmission arrangement.
4. The apparatus of claim 1, wherein the transmission control
circuit is structured to control a pump and a motor, wherein the
transmission is a continuously variable transmission, and wherein
the implement is a front end loader of the vehicle.
5. The apparatus of claim 1, wherein the implement control circuit
is structured to receive information from a user operated
accelerator pedal of the vehicle, and wherein the engine speed is
dependent on the information received from the user operated
accelerator pedal in the implement mode.
6. The apparatus of claim 1, wherein the implement includes a
working hydraulic system and the implement control circuit is
structured to control at least one of a motor and a pump of the
working hydraulic system.
7. The apparatus of claim 1, further comprising a manually operated
switch movable between an implement mode position and a travel mode
position.
8. The apparatus of claim 1, wherein the processing circuit
automatically selects the travel mode or the implement mode based
on receipt of the travel signal or the implement signal.
9. The apparatus of claim 8, wherein the implement signal is
automatically sent when a user interacts with a joystick.
10. The apparatus of claim 1, further comprising a limiting circuit
structured to inhibit use of the implement mode.
11. The apparatus of claim 10, wherein the limiting circuit is
structured to inhibit use of the implement mode when the vehicle is
located on a roadway or travelling above a threshold speed.
12. An apparatus of a vehicle, comprising: a processing circuit
comprising at least one processor coupled to at least one
non-transitory memory device, the processing circuit structured to:
determine a torque reserve; receive one of a travel signal
indicative of a travel mode for the vehicle and an implement signal
indicative of an implement mode for the vehicle; prioritize
propulsion torque over implement torque when the travel signal is
received by limiting implement torque when the torque reserve is
less than or equal to a predetermined threshold; and prioritize
implement torque over propulsion torque when the implement signal
is received by limiting propulsion torque when the torque reserve
is less than or equal to an implement torque predetermined
threshold.
13. The apparatus of claim 12, wherein the implement signal is
automatically sent when a user interacts with an implement of the
vehicle.
14. The apparatus of claim 12, further comprising a working
hydraulic system and a continuously variable transmission, wherein
the processing circuit limits the power consumed by the working
hydraulic system when the travel signal is received, and wherein
the processing circuit limits the power consumed by the
continuously variable transmission when the implement signal is
received.
15. The apparatus of claim 12, wherein the processing circuit is
further structured to: determine a total propulsion torque
estimate; determine a hydraulic torque estimate; determine a torque
demand based at least in part on the total propulsion torque
estimate and the hydraulic torque estimate; and determine a minimum
fuel consumption torque.
16. The apparatus of claim 15, wherein when the travel signal is
received, the processing circuit is structured to decrease an
engine speed when the torque demand is greater than or equal to the
minimum fuel consumption torque, and wherein when the implement
signal is received, the processing circuit is structured to
decrease a requested pump and motor displacement of a working
hydraulic system when the torque demand is greater than or equal to
the minimum fuel consumption torque.
17. The apparatus of claim 12, wherein when the travel signal is
received, the processing circuit is structured to decrease an
engine speed until a torque demand is less than or equal to a
minimum fuel consumption torque, and wherein when the implement
signal is received, the processing circuit is structured to
decrease a requested pump and motor displacement of a working
hydraulic system until the torque demand is less than or equal to
the minimum fuel consumption torque.
18. The apparatus of claim 12, further comprising a limiting
circuit structured to inhibit use of the implement mode.
19. The apparatus of claim 18, wherein the limiting circuit is
structured to inhibit use of the implement mode when the vehicle is
located on a roadway or travelling above a threshold speed.
20. A method, comprising: determining a total propulsion torque
estimate; determining a hydraulic torque estimate; determining a
torque demand based at least in part on the total propulsion torque
estimate and the hydraulic torque estimate; determining a torque
reserve; receiving a travel signal indicative of a travel mode for
a vehicle; receiving an implement signal indicative of an implement
mode for the vehicle; prioritizing propulsion torque over implement
torque when the travel signal is received by limiting implement
torque when the torque reserve is less than or equal to a travel
predetermined threshold; prioritizing implement torque over
propulsion torque when the implement signal is received by limiting
propulsion torque when the torque reserve is less than or equal to
an implement predetermined threshold; decreasing an engine speed
when the torque demand is greater than or equal to a minimum fuel
consumption torque and the travel signal has been received; and
decreasing a requested pump and motor displacement of a working
hydraulic system when the torque demand is greater than or equal to
the minimum fuel consumption torque and the implement signal has
been received.
Description
TECHNICAL FIELD
The present disclosure relates to powertrain control of a vehicle.
More particularly, the present disclosure relates to systems and
methods for controlling a transmission and an implement of a
vehicle.
BACKGROUND
Off-highway vehicles can include continuously variable
transmissions allowing the vehicle to be operated at a number of
ground speeds while running an engine at a constant speed. The
constant speed of the engine can be advantageous to fuel efficiency
of the vehicle. In some situations, a constant engine speed leads
to a lower performance of implements of the vehicle than is
desirable.
SUMMARY
One embodiment relates to an apparatus of a vehicle. The apparatus
includes an engine control circuit structured to control an engine
speed; a transmission control circuit structured to control an
operating parameter of a transmission; an implement control circuit
structured to control an implement; and a processing circuit
structured to receive one of a travel signal indicative of a travel
mode for the vehicle and an implement signal indicative of an
implement mode for the vehicle. In response to receiving the travel
signal indicative of operating in the travel mode, the transmission
control circuit is structured to determine the engine speed and the
implement control circuit limits an implement torque to maintain
the engine speed. In response to receiving the implement signal
indicative of operating in the implement mode, the engine control
circuit is structured to determine the engine speed and the
transmission control circuit limits a propulsion torque to maintain
the engine speed.
Another embodiment relates to an apparatus. The apparatus includes
a processing circuit comprising at least one processor coupled to
at least one non-transitory memory device. The processing circuit
is structured to: determine a torque reserve; receive one of a
travel signal indicative of a travel mode for the vehicle and an
implement signal indicative of an implement mode for the vehicle;
prioritize propulsion torque over implement torque when the travel
signal is received by limiting implement torque when the torque
reserve is less than or equal to a predetermined threshold; and
prioritize implement torque over propulsion torque when the
implement signal is received by limiting propulsion torque when the
torque reserve is less than or equal to an implement torque
predetermined threshold.
Still another embodiment relates to a method. The method includes
determining a total propulsion torque estimate; determining a
hydraulic torque estimate; determining a total demand torque based
at least in part on the total propulsion torque estimate and the
hydraulic torque estimate; determining a torque reserve; receiving
a travel signal indicative of a travel mode for the vehicle;
receiving an implement signal indicative of an implement mode for
the vehicle; prioritizing propulsion torque over implement torque
when the travel signal is received by limiting implement torque
when the torque reserve is less than or equal to a travel
predetermined threshold; prioritize implement torque over
propulsion torque when the implement signal is received by limiting
propulsion torque when the torque reserve is less than or equal to
an implement predetermined threshold; decreasing an engine speed
when the torque demand is greater than or equal to the minimum fuel
consumption torque and the travel signal has been received; and
decreasing a requested pump and motor displacement of a working
hydraulic system when the torque demand is greater than or equal to
the minimum fuel consumption torque and the implement signal has
been received.
These and other features, together with the organization and manner
of operation thereof, will become apparent from the following
detailed description when taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of a vehicle, according to an example
embodiment.
FIG. 2 is a schematic of the functional systems of the vehicle of
FIG. 1, according to an example embodiment.
FIG. 3 is a schematic diagram of a controller of the vehicle of
FIG. 1, according to an example embodiment.
FIG. 4 is a logic flow chart showing a travel mode and an implement
mode, according to an example embodiment.
FIG. 5 is a logic flow chart showing operation in the travel mode,
according to an example embodiment.
FIG. 6 is a logic flow chart showing operation in the implement
mode, according to an example embodiment.
FIG. 7 is a logic flow chart showing operation of the vehicle of
FIG. 1, according to an example embodiment.
DETAILED DESCRIPTION
Following below are more detailed descriptions of various concepts
related to, and implementations of, methods, apparatuses, and
systems for powertrain controls of an engine and a transmission.
The various concepts introduced above and discussed in greater
detail below may be implemented in any number of ways, as the
concepts described are not limited to any particular manner of
implementation. Examples of specific implementations and
applications are provided primarily for illustrative purposes.
Referring to the figures generally, the various embodiments
disclosed herein relate to systems, apparatuses, and methods for
providing prioritized operation during a travel mode and an
implement mode. In the travel mode, engine speed is determined by a
transmission controller and the torque that is available to an
implement (e.g., a front end loader and associated hydraulic
system) is limited. In the implement mode, engine speed is
determined by an engine controller and the torque that is available
for propelling or driving the vehicle (e.g., the torque consumed by
a motor and pump of a continuously variable transmission (CVT)) is
limited. In some embodiments, the system allows for an engine
control during travel that provides improved fuel efficiency and
limits the power available to implements, and implement control
during use in the implement mode that gives the user more
traditional control (e.g., pressing on the accelerator pedal will
directly increase the power available to the implement).
As used within this document, the travel mode refers to a mode of
operation that limits torque provided to an implement and engine
speed is determined by a transmission control circuit. As used
within this document, the implement mode refers to a mode of
operation that limits torque provided to a transmission and engine
speed is determined by an engine control circuit in response to
user input. Within the context of this application, "propulsion
torque" refers to torque provided by an engine that is used to move
a vehicle over the ground, and "implement torque" refers to torque
provide by the engine to any implement of the vehicle (e.g., a
front end loader).
As shown in FIG. 1, a vehicle in the form of a wheel loader 20
generally includes four wheels 24, an engine 28, a cab 32, and an
implement in the form of a front end loader 36. The wheel loader 20
moves over the ground 40 and the front end loader 36 manipulates
material 44. In some constructions, the vehicle is another
off-highway vehicle that includes an implement for manipulating
material. For example, the vehicle may include tracks, a drill, a
rake, a screen and/or conveyor, a bucket, or another implement, as
desired. Within the context of this document, the term implement
refers to any tool or system that consumes power for an action
other than propelling the vehicle for movement over the ground. For
example, the term implement may include, but is not limited to, a
drill/auger, a rake, a conveyor, and/or a bucket.
A shown in FIG. 2, the engine 28 is an internal combustion engine
(e.g., diesel or gasoline) and provides a mechanical power output.
The engine 28 operates at an engine speed and provides an engine
torque. A cooling system 48 is coupled to the engine 28 and
provides heat exchange for the components of the wheel loader 20.
The cooling system 48 includes a fan 52 that can be driven by the
engine 28 that moves air through the cooling system 48. A control
system 56 is positioned within the cab 32 of the wheel loader 20
and includes user interface devices including a steering wheel 60,
an accelerator pedal 64, and a joystick 68. The control system 56
also includes a controller 72 that communicates with the user
interface devices and the other components of the vehicle 20 to
enact control. A working mechanical system 76 includes the front
end loader 36 and the associated linkages. In some embodiments, the
working mechanical system 76 may include mechanically powered
take-offs, other components, or other implements (e.g., a
drill/auger, a drag, a backhoe, a jaw). A working hydraulic system
80 includes a motor/pump 84 and hydraulic actuators 88 that are
coupled to the working mechanical system 76 to enact action to the
working mechanical system 76. The working hydraulic system 80 can
be arranged to operate other components of the working mechanical
system 76. For example, if the working mechanical system 76
includes an auger or another implement, the working hydraulic
system 80 provides power to the implement. In the example of FIG.
2, the implement is coupled to the working mechanical system 75 and
the working hydraulic system 80 together, or to portions of the
working mechanical system 76 and/or the working hydraulic system
80. Additionally, as represented in FIG. 2, the working hydraulic
system 80 includes a steering hydraulic system 89 and a brake
hydraulic system 90. The steering hydraulic system 89 and the brake
hydraulic system 90 are separately controlled but considered a part
of the overall working hydraulic system 80 for purposes of this
document. Further, the working hydraulic system 80 may include
other hydraulic components and systems that require hydraulic power
or flow. A driveline 92 includes a transmission 96 that receives
power from the engine 28 and provides rotational power to the four
wheels 24. In some embodiments, the transmission 96 is a
continuously variable transmission (CVT) that includes a hydraulic
motor/pump.
A typical loader drive cycle for the wheel loader 20 includes five
phases. The first phase is unloaded (e.g., no material in the front
end loader 36) and involves driving or propelling the wheel loader
20 to approach a pile of material 44 or other material 44 location
or area. The second phase includes digging the material 44 and
involves manipulating the working mechanical system 76 via the
working hydraulic system 80 and propelling the wheel loader 20 with
the driveline 92. The third phase is loaded (e.g., the front end
loader 36 is filled with material) and involves reversing or
propelling the wheel loader 20 away from the pile of material 44 or
other material 44 location or area. The fourth phase including
approaching a dump site (e.g., a truck, a second location or area,
a train car) and involves raising the front end loader 36 with the
working mechanical system 76 via the working hydraulic system 80,
and propelling the wheel loader 20 forward. The fifth phase
includes stopping the wheel loader 20 an appropriate distance from
the dump site, manipulating the working mechanical system 76 via
the working hydraulic system 80 to dump the material 44 from the
front end loader 36, and lowering the front end loader 36 to
prepare for another loader drive cycle.
During a typical loader drive cycle, the cooling system 48, the
working hydraulic system 80, and the driveline 92 all consume power
provided by the engine 28 and compete for available power
simultaneously. FIG. 2 shows the systems of the wheel loader 20
connected to the engine 28 and drawing power therefrom. According
to the present disclosure, the controller 72 is arranged to operate
the wheel loader 20 in a travel mode when the wheel loader is
primarily driving over the ground and in an implement mode when the
wheel loader is primarily operating an implement. In the travel
mode, the controller 72 provides priority to the driveline 92 for
torque demand, and in the implement mode, the controller provides
priority to the working hydraulic system 80 for torque demand.
As shown in FIG. 3, the controller 72 of the control system 56 can
be embodied in the wheel loader 20. The controller 72 may be
structured as one or more electronic control units (ECU). The
controller 72 may be separate from or included with at least one of
a transmission control unit, an exhaust aftertreatment control
unit, a powertrain control module, an engine control module, etc.
The schematic diagram of the controller 72 referred to with
reference to FIG. 3 is shown according to an example embodiment. As
shown in FIG. 3, the controller 72 includes a processing circuit
100 having a processor 104 and a memory device 108, a control
system 112 having an engine control circuit 116, a transmission
control circuit 120, and an implement control circuit 124, and a
communications interface 128. Generally, the controller 72 is
structured to provide prioritized operation during a travel mode
and an implement mode. In the travel mode, engine speed is
determined by the transmission control circuit 120 and the torque
that is available to implements (e.g., the front end loader 36) is
limited. In the implement mode, engine speed is determined by the
engine control circuit 116 and the torque that is available for
propelling or driving the wheel loader 20 (e.g., the torque
consumed by a motor and pump of the transmission 96) is limited. In
some embodiments, the controller 72 provides improved fuel
efficiency and limits the power available to implements during
travel mode operation, and provides the user with a more
traditional control (e.g., pressing on the accelerator pedal will
directly increase the power available to the implement) during
implement mode operation.
In one configuration, the engine control circuit 116, the
transmission control circuit 120, and the implement control circuit
124 are embodied as machine or computer-readable media that is
executable by a processor, such as processor 104. As described
herein and amongst other uses, the machine-readable media
facilitates performance of certain operations to enable reception
and transmission of data. For example, the machine-readable media
may provide an instruction (e.g., command, etc.) to, e.g., acquire
data. In this regard, the machine-readable media may include
programmable logic that defines the frequency of acquisition of the
data (or, transmission of the data). The computer readable media
may include code, which may be written in any programming language
including, but not limited to, Java or the like and any
conventional procedural programming languages, such as the "C"
programming language or similar programming languages. The computer
readable program code may be executed on one processor or multiple
remote processors. In the latter scenario, the remote processors
may be connected to each other through any type of network (e.g.,
CAN bus, etc.).
In another configuration, the engine control circuit 116, the
transmission control circuit 120, and the implement control circuit
124 are embodied as hardware units, such as electronic control
units. As such, the engine control circuit 116, the transmission
control circuit 120, and the implement control circuit 124 may be
embodied as one or more circuitry components including, but not
limited to, processing circuitry, network interfaces, peripheral
devices, input devices, output devices, sensors, etc. In some
embodiments, the engine control circuit 116, the transmission
control circuit 120, and the implement control circuit 124 may take
the form of one or more analog circuits, electronic circuits (e.g.,
integrated circuits (IC), discrete circuits, system on a chip
(SOCs) circuits, microcontrollers, etc.), telecommunication
circuits, hybrid circuits, and any other type of "circuit." In this
regard, the engine control circuit 116, the transmission control
circuit 120, and the implement control circuit 124 may include any
type of component for accomplishing or facilitating achievement of
the operations described herein. For example, a circuit as
described herein may include one or more transistors, logic gates
(e.g., NAND, AND, NOR, OR, XOR, NOT, XNOR, etc.), resistors,
multiplexers, registers, capacitors, inductors, diodes, wiring, and
so on). The engine control circuit 116, the transmission control
circuit 120, and the implement control circuit 124 may also include
programmable hardware devices such as field programmable gate
arrays, programmable array logic, programmable logic devices or the
like. The engine control circuit 116, the transmission control
circuit 120, and the implement control circuit 124 may include one
or more memory devices for storing instructions that are executable
by the processor(s) of the engine control circuit 116, the
transmission control circuit 120, and the implement control circuit
124. The one or more memory devices and processor(s) may have the
same definition as provided below with respect to the memory device
108 and processor 104. In some hardware unit configurations, the
engine control circuit 116, the transmission control circuit 120,
and the implement control circuit 124 may be geographically
dispersed throughout separate locations in the vehicle.
Alternatively and as shown, the engine control circuit 116, the
transmission control circuit 120, and the implement control circuit
124 may be embodied in or within a single unit/housing, which is
shown as the controller 72.
In the example shown, the controller 72 includes a processing
circuit 100 having a processor 104 and a memory device 108. The
processing circuit 100 may be structured or configured to execute
or implement the instructions, commands, and/or control processes
described herein with respect to the engine control circuit 116,
the transmission control circuit 120, and the implement control
circuit 124. The depicted configuration represents the engine
control circuit 116, the transmission control circuit 120, and the
implement control circuit 124 as machine or computer-readable
media. However, as mentioned above, this illustration is not meant
to be limiting as the present disclosure contemplates other
embodiments where the engine control circuit 116, the transmission
control circuit 120, and the implement control circuit 124, or at
least one circuit of the engine control circuit 116, the
transmission control circuit 120, and the implement control circuit
124, is configured as a hardware unit. All such combinations and
variations are intended to fall within the scope of the present
disclosure.
The processor 104 may be implemented as one or more general-purpose
processor, an application specific integrated circuit (ASIC), one
or more field programmable gate arrays (FPGAs), a digital signal
processor (DSP), a group of processing components, or other
suitable electronic processing components. In some embodiments, the
one or more processors may be shared by multiple circuits (e.g.,
the engine control circuit 116, the transmission control circuit
120, and the implement control circuit 124 may comprise or
otherwise share the same processor which, in some example
embodiments, may execute instructions stored, or otherwise
accessed, via different areas of memory). Alternatively or
additionally, the one or more processors may be structured to
perform or otherwise execute certain operations independent of one
or more co-processors. In other example embodiments, two or more
processors may be coupled via a bus to enable independent,
parallel, pipelined, or multi-threaded instruction execution. All
such variations are intended to fall within the scope of the
present disclosure. The memory device 108 (e.g., RAM, ROM, Flash
Memory, hard disk storage, etc.) may store data and/or computer
code for facilitating the various processes described herein. The
memory device 108 may be communicably connected to the processor
104 to provide computer code or instructions to the processor 104
for executing at least some of the processes described herein.
Moreover, the memory device 108 may be or include tangible,
non-transient volatile memory or non-volatile memory. Accordingly,
the memory device 108 may include database components, object code
components, script components, or any other type of information
structure for supporting the various activities and information
structures described herein.
The engine control circuit 116 is structured to receive signals
(e.g., data, values, information) from the control system 56
including the steering wheel 60, the accelerator pedal 64, and the
joystick 68 via the communication interface 128, and provides
command signals (e.g., data, values, information) to the engine 28
via the communication interface 128. In some embodiments, the
engine control circuit 116 is structured to control, manage,
operate, or otherwise affect operation of an ignition system, an
ignition timing, an air intake system, a fueling system, or another
system of the engine 28.
The transmission control circuit 120 is structured to receive
signals (e.g., data, values, information) from the control system
56 including the steering wheel 60, the accelerator pedal 64, and
the joystick 68 via the communication interface 128, and provides
command signals (e.g., data, values, information) to the
transmission 96 via the communication interface 128. In some
embodiments, the transmission control circuit 120 is structured to
control, manage, operate, or otherwise affect operation of the
transmission 96 and/or other components of the driveline 92. For
example, the transmission control circuit 120 can control the
motor/pump displacement of a continuously variable transmission
(CVT) thereby affecting the speed of the wheel loader 20 over the
ground 42.
The implement control circuit 124 is structured to receive signals
(e.g., data, values, information) from the control system 56
including the steering wheel 60, the accelerator pedal 64, and the
joystick 68 via the communication interface 128, and provides
command signals (e.g., data, values, information) to the working
hydraulic system 80 via the communication interface 128. In some
embodiments, the implement control circuit 124 is structured to
control, manage, operate, or otherwise affect operation of the
working hydraulic system 80 and/or the working mechanical system
76. For example, when the joystick 68 is manipulated, the implement
control circuit 124 instructs the front end loader 36 to respond
accordingly.
As shown in FIG. 4, an operator or user 132 interacts with the
control system 56 by manipulating the accelerator pedal 64 and the
joystick 68. In some embodiments, the joystick 68 is used for
controlling an implement (e.g., the front end loader 36) and is
used to select a travel mode 136 or an implement mode 140. In some
embodiments, the implement control circuit 124 recognizes a
joystick signal 144 when the user 132 is manipulating the joystick
68 and causes the controller 72 to enter the implement mode 140. In
some embodiments, the joystick 68 includes a switch 146 that can be
manipulated by the user 132 to manually select either the travel
mode 136 or the implement mode 140. In some embodiments, the
controller 72 may include a limiting circuit that inhibits a user
from selecting the implement mode 140. For example, the implement
mode 140 may be disabled while the wheel loader 20 is on a roadway,
or if the wheel loader is travelling at or above a threshold
speed.
As shown in FIG. 5, while operating in the travel mode 136, the
engine control circuit 116 receives an input (if any) from the
implement control circuit 124 and provides a recommended engine
speed and an available torque reserve to the transmission control
circuit 120. The transmission control circuit 120 receives the
recommended engine speed and the available torque reserve from the
engine control circuit 116, and determines a pump/motor
displacement and an engine speed that are then provided back to the
engine control circuit 116. The engine control circuit 116 then
utilizes the engine speed determined by the transmission control
circuit 120 and operates the engine 28 accordingly. The
transmission control circuit 120 then controls the transmission 96
(e.g., the pump/motor of a CVT) of the driveline 92. In the travel
mode 136, priority is given to propulsion torque and the
transmission 96 may be operated for maximum fuel efficiency. In
some embodiments, if the user 132 operates an implement of the
wheel loader 20 (e.g., the front end loader 36) while operating in
the travel mode 136, the controller 72 provides torque to the
working hydraulic system 80 only after any required propulsion
torque has been provided. In some embodiments, if the user 132
operates an implement of the wheel loader 20 while operating in the
travel mode 136, the controller 72 will limit the implement torque
in order to meet or substantially meet the desired propulsion
torque.
As shown in FIG. 6, while operating in the implement mode 140, the
engine control circuit 116 and the transmission control circuit 120
receive inputs from the implement control circuit 124. The engine
control circuit 116 provides an available torque and a minimum fuel
consumption (best efficiency) torque to the transmission control
circuit 120. The minimum fuel consumption (best efficiency) torque
represents a value of torque that the engine 28 can provide while
operating at a maximum fuel efficiency. The transmission control
circuit 120 determines a required pump/motor displacement of the
driveline 92 including the transmission 96 and provides a
pump/motor displacement signal (e.g., instruction, data, values,
information) to the engine control circuit 116. The engine control
circuit 116 then determines an engine speed based on the inputs
from the implement control circuit 124 (e.g., the needs of the
working hydraulic system 80) and the communication pump/motor
displacement from the transmission control circuit 120. The engine
28 is then controlled to the engine speed determined by the engine
control circuit 116. In the implement mode 140, priority is given
to implement torque and the user 132 more directly impacts the
engine speed by manipulating the accelerator pedal 64. In other
words, the implement mode 140 provides the user 132 with the
ability to speed up or slow down the speed of the engine 28
manually to meet the demands of the implements (e.g., the front end
loader 36) while operating in the implement mode 140. In some
embodiments, if the user 132 moves the wheel loader 20 (e.g., the
front end loader 36) while operating in the implement mode 140, the
controller 72 will provide propulsion torque to the driveline 92
only after any required implement torque has been provided. In some
embodiments, if the user 132 moves the wheel loader 20 while
operating in the implement mode 140, the controller 72 will limit
the propulsion torque in order to meet the desired implement
torque.
A method 148 of operating the wheel loader 20 is shown in FIG. 7.
At a start 152 of the method 148, the transmission control circuit
120 determines a ground speed of the wheel loader 20 based on input
received from a ground speed sensor at step 156, and determines a
machine weight of the wheel loader 20 based on input received from
strain gauges, other sensors, and/or manual input at step 160. The
ground speed and machine weight can be determined based on
information received from virtual sensors, or other calculations
that are based on values determined by other vehicle systems,
within the controller 72, or by another controller. The
transmission control circuit 120 then determines a steady state
torque estimate to maintain the current speed at step 164, and an
acceleration torque estimate to accelerate or decelerate in
response to a request from the user 132 (e.g., pressing the
accelerator pedal or a brake pedal) at step 168. At step 172, the
transmission control circuit 120 determines a total propulsion
torque estimate based on the determined steady state propulsion
torque estimate and the acceleration torque estimate.
At step 176, the implement control circuit 124 determines an
implement torque or a hydraulic torque estimate based on feedback
from the working hydraulic system 80. The controller 72 then
determines a total torque demand (TD) at step 180 based on the
hydraulic torque estimate and the total propulsion torque estimate.
Previous steps are included to estimate or predict steady state
engine torque (e.g., a sum of propulsion and implement hydraulic
torque). Alternatively, total torque demand can be current torque
demand on engine.
At step 184, the engine control circuit 116 receives an engine
speed request (e.g., to increase or decrease the engine speed) from
the user 132 (e.g., from the accelerator pedal 64 or the joystick
68). At step 188, the engine control circuit 116 determines a
maximum torque available from the engine 28 and at step 192 the
engine control circuit 116 determines a minimum fuel consumption
(best efficiency) torque (minFC). The engine control circuit 116
then determines an available torque reserve (TR) based on the total
torque demand (TD) and the maximum torque available, at step
196.
At step 200, the controller 72 determines if the travel mode 136 or
the implement mode 140 is active. If the travel mode 136 is active,
then the method 148 proceeds to step 204 and the torque reserve
(TR) is compared to a predetermined threshold (X) to determine if
the engine 28 can produce enough torque to operate the wheel loader
20 without limiting any systems. If the torque reserve (TR) is less
than or equal to the predetermined threshold (X), then the
implement control circuit 124 will actively limit the implement
torque used by the working hydraulic system 80 at step 208. If the
controller 72 determines at step 204 that the torque reserve (TR)
is greater than or equal to the predetermined threshold (X), then
the method 148 continues to step 212 and the total torque demand
(TD) is compared to the minimum fuel consumption (best efficiency)
torque (minFC). If the total torque demand (TD) is less than or
equal to the minimum fuel consumption (best efficiency) torque
(minFC), then the transmission control circuit 120 makes no demand
for a speed change at step 216. If the total torque demand (TD) is
greater than or equal to the minimum fuel consumption (best
efficiency) torque (minFC), then the transmission control circuit
120 communicates with the engine control circuit 116 to reduce the
engine speed at step 220. At step 224, the transmission control
circuit 120 determines if the total torque demand (TD) is less than
or equal to the minimum fuel consumption (best efficiency) torque
(minFC). If not, then the method 148 returns to step 220 and the
transmission control circuit 120 again requests a decrease in the
engine speed. Steps 220 and 224 are repeated iteratively until the
total torque demand (TD) is less than or equal to the minimum fuel
consumption (best efficiency) torque (minFC), then no further
change is requested and the method proceeds to step 216.
If at step 200, the implement mode 140 is active, then the method
148 proceeds to step 228 and the torque reserve (TR) is compared to
the predetermined threshold (X). If the torque reserve (TR) is less
than or equal to the predetermined threshold (X), then the
transmission control circuit 120 will actively limit the propulsion
torque used by the driveline 92 at step 232. If the controller 72
determines at step 228 that the torque reserve (TR) is greater than
or equal to the predetermined threshold (X), then the method 148
continues to step 236 and the total torque demand (TD) is compared
to the minimum fuel consumption (best efficiency) torque (minFC).
If the total torque demand (TD) is less than or equal to the
minimum fuel consumption (best efficiency) torque (minFC), then the
engine control circuit 116 makes no demand for a speed change at
step 216. If the total torque demand (TD) is greater than or equal
to the minimum fuel consumption (best efficiency) torque (minFC),
then the engine control circuit 116 determines a reduces engine
speed at step 240. At step 244, the implement control circuit 124
determines if the total torque demand (TD) is less than or equal to
the minimum fuel consumption (best efficiency) torque (minFC). If
not, then the method 148 returns to step 240 and the engine control
circuit 116 again requests a decrease in the engine speed. Steps
240 and 244 are repeated iteratively until the total torque demand
(TD) is less than or equal to the minimum fuel consumption (best
efficiency) torque (minFC), then no further change is requested and
the method proceeds to step 216.
The method 148 reduces the incidence of engine stalling by limiting
either the propulsion torque or the implement torque and provides
increased operator 132 control while in the implement mode 140. The
working modes (i.e., the travel mode 136 and the implement mode
140) provide a priority operation. In the travel mode 136,
propulsion torque is prioritized, and in the implement mode 140,
implement torque is prioritized.
For the purpose of this disclosure, the term "coupled" means the
joining or linking of two members directly or indirectly to one
another. Such joining may be stationary or moveable in nature. For
example, a propeller shaft of an engine "coupled" to a transmission
represents a moveable coupling. Such joining may be achieved with
the two members or the two members and any additional intermediate
members. For example, circuit A communicably "coupled" to circuit B
may signify that the circuit A communicates directly with circuit B
(i.e., no intermediary) or communicates indirectly with circuit B
(e.g., through one or more intermediaries).
While various circuits with particular functionality are shown in
FIG. 3, it should be understood that the controller 72 may include
any number of circuits for completing the functions described
herein. For example, the activities and functionalities of the
circuits 116, 120, 124 may be combined in multiple circuits or as a
single circuit. Additional circuits with additional functionality
may also be included. Further, the controller 72 may further
control other activity beyond the scope of the present
disclosure.
As mentioned above and in one configuration, the "circuits" may be
implemented in machine-readable medium for execution by various
types of processors, such as processor 104 of FIG. 3. An identified
circuit of executable code may, for instance, comprise one or more
physical or logical blocks of computer instructions, which may, for
instance, be organized as an object, procedure, or function.
Nevertheless, the executables of an identified circuit need not be
physically located together, but may comprise disparate
instructions stored in different locations which, when joined
logically together, comprise the circuit and achieve the stated
purpose for the circuit. Indeed, a circuit of computer readable
program code may be a single instruction, or many instructions, and
may even be distributed over several different code segments, among
different programs, and across several memory devices. Similarly,
operational data may be identified and illustrated herein within
circuits, and may be embodied in any suitable form and organized
within any suitable type of data structure. The operational data
may be collected as a single data set, or may be distributed over
different locations including over different storage devices, and
may exist, at least partially, merely as electronic signals on a
system or network.
While the term "processor" is briefly defined above, the term
"processor" and "processing circuit" are meant to be broadly
interpreted. In this regard and as mentioned above, the "processor"
may be implemented as one or more general-purpose processors,
application specific integrated circuits (ASICs), field
programmable gate arrays (FPGAs), digital signal processors (DSPs),
or other suitable electronic data processing components structured
to execute instructions provided by memory. The one or more
processors may take the form of a single core processor, multi-core
processor (e.g., a dual core processor, triple core processor, quad
core processor, etc.), microprocessor, etc. In some embodiments,
the one or more processors may be external to the apparatus, for
example the one or more processors may be a remote processor (e.g.,
a cloud based processor). Alternatively or additionally, the one or
more processors may be internal and/or local to the apparatus. In
this regard, a given circuit or components thereof may be disposed
locally (e.g., as part of a local server, a local computing system,
etc.) or remotely (e.g., as part of a remote server such as a cloud
based server). To that end, a "circuit" as described herein may
include components that are distributed across one or more
locations.
Although the diagrams herein may show a specific order and
composition of method steps, the order of these steps may differ
from what is depicted. For example, two or more steps may be
performed concurrently or with partial concurrence. Also, some
method steps that are performed as discrete steps may be combined,
steps being performed as a combined step may be separated into
discrete steps, the sequence of certain processes may be reversed
or otherwise varied, and the nature or number of discrete processes
may be altered or varied. The order or sequence of any element or
apparatus may be varied or substituted according to alternative
embodiments. All such modifications are intended to be included
within the scope of the present disclosure as defined in the
appended claims. Such variations will depend on the
machine-readable media and hardware systems chosen and on designer
choice. All such variations are within the scope of the
disclosure.
The foregoing description of embodiments has been presented for
purposes of illustration and description. It is not intended to be
exhaustive or to limit the disclosure to the precise form
disclosed, and modifications and variations are possible in light
of the above teachings or may be acquired from this disclosure. The
embodiments were chosen and described in order to explain the
principals of the disclosure and its practical application to
enable one skilled in the art to utilize the various embodiments
and with various modifications as are suited to the particular use
contemplated. Other substitutions, modifications, changes and
omissions may be made in the design, operating conditions and
arrangement of the embodiments without departing from the scope of
the present disclosure as expressed in the appended claims.
Accordingly, the present disclosure may be embodied in other
specific forms without departing from its spirit or essential
characteristics. The described embodiments are to be considered in
all respects only as illustrative and not restrictive. The scope of
the disclosure is, therefore, indicated by the appended claims
rather than by the foregoing description. All changes which come
within the meaning and range of equivalency of the claims are to be
embraced within their scope.
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